Recent improvements in solid state CW lasers, recording materials and light sources (such as LED lights) for displaying colour holograms are described. Full-color analogue holograms can now be created with substantially better image characteristics than previously possible. To record ultra-realistic images depends on selecting the optimal recording RGB laser wavelengths. Analogue color holograms of the Denisyuk type are the ones which really create the illusion of viewing a real object behind the plate rather than an image of it. It is necessary to use extremely low-light-scattering panchromatic recording materials, which means the use of ultra-fine-grain, silver-halide emulsions. The third factor is the light source used to display the recorded color holograms. Progress in illumination technology, by employing the new LED lights, is leading to a further major reduction in display noise and to a significant increase of the clear image depth and brightness of the holograms. Recording and displaying color holograms (referred to as OptoClones™) of museum artefacts are described.

Recent improvements in solid state CW lasers, recording materials and light sources (such as LED lights) for displaying
color holograms are described. Full-color analogue holograms can now be created with substantially better image
characteristics than previously possible. To record ultra-realistic images depends on selecting the optimal recording laser
wavelengths and employing ultra-fine-grain, silver-halide materials. The image quality is improved by using LED
display light with improved spatial coherence. Recording museum artifacts using mobile holographic equipment is
described. The most recent recorded such holograms (referred to as OptoClones™) are the Fabergé Eggs at the Fabergé
Museum in St. Petersburg, Russia.

Ultrarealistic imaging is the science of producing images that faithfully recreate the light field surrounding an object, such that the unaided eye of a human observer cannot distinguish the difference between the original and the image. Recent technology improvements are now set to transform the fields of both analog and digital display holography, permitting both techniques to operate in the ultrarealistic regime. In particular, ultrarealistic analog holograms have now heralded the serious use of holography in such areas as museum display and cultural heritage protection. These full-color holograms are characterized by a substantially lower noise and a greater spectral fidelity. New recording systems, based on recent diode-pumped solid-state and semiconductor lasers combined with recording materials and processing, have been behind these improvements. Progress in illumination technology, however, has also led to a major reduction in display noise and to a significant increase in the clear image depth and brightness of holograms. Recent progress in one-step direct-write digital holography (DWDH) is now also opening the way to the creation of a new type of ultrarealistic display: the high virtual volume display. This is a large format full-parallax DWDH reflection hologram having a fundamentally larger clear image depth.

Recent improvements in key foundation technologies are set to potentially transform the field of Display Holography. In particular new recording systems, based on recent DPSS and semiconductor lasers combined with novel recording materials and processing, have now demonstrated full-color analogue holograms of both lower noise and higher spectral accuracy. Progress in illumination technology is leading to a further major reduction in display noise and to a significant increase of the clear image depth and brightness of such holograms. So too, recent progress in 1-step Direct-Write Digital Holography (DWDH) now opens the way to the creation of High Virtual Volume Displays (HVV) - large format full-parallax DWDH reflection holograms having fundamentally larger clear image depths. In a certain fashion HVV displays can be thought of as providing a high quality full-color digital equivalent to the large-format laser-illuminated transmission holograms of the sixties and seventies. Back then, the advent of such holograms led to much optimism for display holography in the market. However, problems with laser illumination, their monochromatic analogue nature and image noise are well cited as being responsible for their failure in reality. Is there reason for believing that the latest technology improvements will make the mark this time around? This paper argues that indeed there is.

Progress has been made towards the development of a flexible true color holographic imaging device for direct optical biopsy. This can potentially be used for surgical techniques employing direct visualization, including endoscopy and laparoscopy. A novel panchromatic ‘ultrahigh precision’ recording media, with a thin layer of ultrafine grain of silver halide crystals of 10-20 nm average diameter, has been utilized. The significance of the development so far, has been the ability to emulate ‘color optical biopsy’ providing useful information of ‘medical relevance’.

A review of recent improvements and applications in color holography is provided. Color holography recording techniques
in silver-halide emulsions and photopolymer materials are discussed. Both analogue Denisyuk color holograms and
digitally-printed color holograms are described. The light sources used to illuminate the recorded holograms are very
important to obtain ultra-realistic 3D images. In particular the new light sources based on RGB LEDs are significant
improvements in displaying color holograms with improved image quality over today’s commonly used halogen lights.
Color holograms of museum artifacts have been recorded with new mobile holographic equipment.

Color display holography, which is the most accurate imaging technology known to science, has been used to produce
holographic images for display of artifacts in museums. This article presents the 'Bringing the Artifacts back to the
people' project. Holograms of twelve different artifacts were recorded using the single-beam Denisyuk color reflection
hologram technique. 'White' laser light was produced from three combined cw RGB lasers: a red krypton-ion laser, a
green frequency-doubled Nd-YAG laser, and an argon-ion laser. Panchromatic ultra-fine-grain silver halide materials
were used for the recording of the holograms. During 2009 the artifacts were brought to St Asaph in Wales at the Centre
for Modern Optics, to undergo holographic recording. One of the recorded artifacts included a 14,000-year-old
decorated horse jaw bone from the ice age, which is kept at British Museum in London. The recorded color holograms
of this object and others have been arranged in a touring exhibition, the 'Virtual Artifacts Exhibition.' During 2010-
2011, this will be installed in a number of local museums in North Wales and surrounding areas.

Color holography is the most accurate imaging technology known to science. It is possible to produce holographic
images that are almost identical to the original scene. Color holograms and holographic optical elements (HOEs) are
becoming increasingly attractive. Since the 1990s the developments in other technology areas have created many
potential new applications for color holograms and HOEs but again these new market areas are unexploited due to the
lack of a suitable color holographic recording material. This restricts the commercial and technical development and
exploitation of holographic-based industries, applications, techniques and processes. There is not a sufficient,
commercial recording material for color holograms and HOEs. Most of the materials that are in use at present have
relative poor performance and many manufacture methods of the materials are limited to laboratory scale. This paper
presents fabrication details of ultra-fine grain (5 -10 nm), high sensitivity (less than 2.0 mJcm-2), low light-scattering,
panchromatic silver halide emulsions. Such materials can be used for high-quality 3-D imaging recording techniques,
including color holograms and HOEs. A comprehensive approach regarding all aspects of the emulsion preparation, from
the precipitation of the silver halide crystals to sensitization and coating is provided. There are also recommendations
regarding the processing of the material in order to achieve optimum performance.

The first methods for recording color holograms were established in the early 1960s. Leith and Upatnieks proposed
multicolor wavefront reconstmction and Denisyuk introduced the single-beam reflection holography technique which is
most suitable for recording color holograms today. Reviewed is the history of color holography highlighting important
milestones. The current state-of-the-art of color holography is presented including the recording techniques using red, green
and blue laser wavelengths. The laser wavelength selection issue is presented using computer simulation, showing that more
than three wavelengths may be needed for accurate color rendition in holograms. The recording material is a key factor very
important for creating high-quality color holograms. Covered are both the demand on the material and suitable products
currently on the market. The future of color holography is highly dependent on the availability of improved panchromatic
recording materials and suitable light sources for displaying the holograms. Small laser diodes as well as powerful white
LEDs and OLEDs with very limited source diameters are important for color holography to become an important 3D display
medium.

Holography is an imaging technique which accurately can record both the amplitude and the phase of the scattered light
from an object. However, to obtain a hologram in which both the 3D shape and the color of the object are required to be
accurately reproduced, the recording of the hologram has to be performed by using at least three laser wavelengths. A mathematical model has been generated in order to simulate the holographic color rendering process by assuming ideal laser recording and reconstruction conditions which ignores the influence caused by the recording material and the processing. Based on this mathematical model a computer program with appropriate graphical user interface was
implemented. The required amount of laser wavelengths and their distribution within the visible electromagnetic spectrum has been investigated in order to obtain the best possible color rendering. Simulations using three to seven laser wavelengths have been performed to better understand the sampling nature of color holography and by performing multiple simulations for all possible laser selections the optimum wavelengths have been obtained. We have found that three wavelengths are only sufficient if chosen carefully, but for improved color rendering four to five wavelengths are
recommended.

Lippmann photographs can, in principle, reproduce the entire incident spectrum at every point in the recording.
This paper presents a comprehensive model of the Lippmann process, including exposure, chemical processing
and subsequent reproduction. The main emphasis is on the optical properties of emulsions, where the theory of
radiative transfer is used to obtain a detailed description of how interference patterns are formed in the presence
of scattering particles and absorption. The results presented illustrate the reproduction fidelity of Lippmann
photographs and highlight the most significant factors influencing their quality. Whereas the reproduction of
monochrome sources is excellent, locally broadband signals are more problematic. Several practical measures to
improve upon broadband performance are discussed.

Two imaging techniques are presented which can create remarkable images. The first technique is color holography which provides full parallax 3D color images with a large field of view. The virtual color image recorded in a holographic plate represents the most realistic-looking image of an object that can be obtained today. The extensive field of view adds to the illusion of beholding a real object rather than an image of it. The other technique is interferential color photography or Lippmann photography. This, almost forgotten, one-hundred-year-old photographic technique, is also remarkable. It is the only color recording imaging technique, which can be record the entire visible color spectrum. It is not based on Maxwell's three- color principle, the dominating principle behind most current color imaging techniques. The natural color rendition, make this 2D photographic technique very interesting. The reproduction of human skin and metallic reflections, for example, are very natural looking, which is not possible to record in ordinary photography.

Until recently, display holography was usually associate with 3D imaging. After the appearance of color holography it has become possible, however, to record holographic images of 2D objects, such as, for example, oil paintings. The realistic-looking virtual image recorded in a Denisyuk reflection hologram is the most suitable for such reproductions. A holographic contact recording of a painting reproduces the painting with all its texture details preserved, such as brush strokes, the painter's signature, etc. This means that an exact copy of the painting can be made, which can then be displayed at art exhibitions, museums, etc., when the original is not available. If an expensive painting is concerned, possessing an exact copy of the painting may also be important for insurance purposes, in case the painting is stolen or damaged. The advantage of a color contact hologram is that the hologram reconstruction process can be relaxed, as there is no need of spatial coherence of the white light source used to illuminate the hologram. In addition, no depth distortions are introduced as a function of the light source's distance from the plate. Only the angel of illumination is of primary importance if good color reproduction is to be obtained. The paper discusses the rendition of color in hologram, which is extremely important in this case. The holographic reproduction process of an oil painting is also described, and the major advantages of holographic reproduction are discussed together with its limitations.

The recording and processing technique for color HOEs in ultrafine-grain panchromatic silver halide emulsions is presented. It is possible to obtain high diffraction efficiency employing the silver halide sensitized gelatin (SHSG) process. SHSG holograms are similar to holograms recorded in dichromated gelatin (DCG). The drawback of DCG is its low sensitivity and limited spectral response. Panchromatic silver halide materials from Slavich can be processed in such a way that the final holograms have properties like a DCG hologram. The processing method or microvoid technique has been optimized for three laser- wavelength recordings in Slavich PFG-03C emulsion. For example, applying this new processing technique high- efficiency white holographic reflectors can be manufactured. The technique is also suitable for producing efficiency color display holograms. In particular, masters for mass production of color holograms or color HOEs can be performed by contact-copying into photopolymer materials because the reconstruction wavelengths are identical to the recording wavelengths.

The old Lippmann color photography technique has been investigated. Today, high-resolution panchromatic recording materials are on the market suitable for Lippmann photography. The holographic panchromatic silver-halide materials from Slavich in Russia, as well as the panchromatic photopolymers from DuPont in the USA can be used for recording Lippmann photographs. In particular, the Slavich emulsion has been investigated for recoding Lippmann photographs. In order to understand the Lippmann technique better, computer simulations of the recording and reconstruction process have been undertaken. A Lippmann color photograph is unique and almost impossible to copy, which makes it suitable for the document security application. A new optical variable device (OVD) technique is under development. This type of photograph can be applied to personal documents as a new optical security device, e.g., passports, ID cards, etc., can carry a Lippmann OVD. The recording of a Lippmann photograph requires a special panchromatic recording material, e.g., silver halide materials or photopolymer materials.

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra- fine grain silver halide (AgHal) emulsions. In particular, high spatial frequency fringes associated with HOEs of the reflection type are difficult to convert employing SHSG processing methods. Therefore, an optimized processing techniques for reflection HOEs recorded in the new AgHal- materials is introduced. Diffraction efficiencies over 90 percent can be obtained for both transmission and reflection diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, including also high-quality display holograms of the reflection type, both monochrome and full color.

Collecting postage stamps is a worldwide business and hobby, which begun not long after national post offices started to issue stamps. The very first definitive stamp with a hologram was issued in Austria in 1988. Since then, about 40 countries have issued holographic stamps and the total amount of different postal items with holograms is about 100. In 1999, there were more holographic stamps issued than in any previous years. A chronological review of stamps issued with embossed holograms is given. A detailed description of each stamp is provided with photographs of all postage stamps and souvenir sheets. The use of holograms on stamps seems to be more of a new and attractive decoration rather than a security measure. Holographic stamps have already become a new philatelic topical field.

The possibility to easily record full color holograms, (simply color holograms) has opened new possibilities for art holographers. This paper includes details concerning preparation of subject matter and its practical suitability for color holographic recordings from practical working sessions at ARTCAPI Atelier de Recherche Technique et de Creation Artistique en Physique et en Informatique in France. Martin Richardson as invited artist and Hans Bjelkhagen as scientist holographer describe color holography to a wider public audience through artistic display. Both directly recorded true color images and computer-generated images based on the ZEBRA printing technique are to be presented.

A new Optical Variable Device (OVD) technique is presented: the Lippmann OVD, based on interferential color photography. A system is under development where this type of unique photograph can be applied to personal documents as a new security device. For example, passports, travel documents, identification cards, driving licences, credit cards can carry a laminated Lippmann OVD. The Lippmann photograph is similar to the mass-produced embossed holograms, currently used in this field. However, each document can have its unique Lippmann OVD. The recording of the Lippmann OVD requires a special panchromatic photopolymer material as well as a special type of recording equipment. The main advantage of this new OVD is that it can be produced in- house by the document issuer. Lippmann OVDs are virtually impossible to copy and, certainly, cannot be copied by conventional photography or color copying machines. In addition, the authenticity of the Lippmann OVD can be verified by direct visual inspection, without the need for any equipment.

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawbacks of DCG is its low sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently, this technique has become more interesting after the introduction of the new ultra-high-resolution silver halide emulsions. An optimized processing technique for transmission HOEs recorded in these materials is reported. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high sensitivity recording can be performed employing laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs.

A new Optical Variable Device (OVD) based on an old color photographic technique (Lippmann photography, invented in 1891) is presented. Today, this type of photography can be applied as a unique security device on security documents, such as, e.g., identification cards, passports, credit cards, and other documents where a high degree of security is needed. A Lippmann photograph is very similar to holograms, currently used in this field; a unique recording of each document can be made to achieve a degree of security higher than that with mass-produced holograms. The recording of Lippmann photographs requires a special type of photosensitive medium in contact with a reflecting layer. Panchromatic silver-halide or photopolymer materials can be used and, after being recorded and processed, laminated to security documents. A special type of recording equipment is required. Lippmann photographs are virtually impossible to copy and, certainly, cannot be copied by conventional photography or color copying machines.

The recording technique of Denisyuk color reflection holograms has been simplified by using `white' laser light. The Slavich red-green-blue (RGB) sensitized ultra-high resolution silver halide emulsion was used for the hologram recording. The employed laser wavelengths were 633 nm, 531 nm, and 476 nm, generated by a helium-neon, a mixed argon- krypton ion, and an argon ion laser, respectively. A beam combination mechanism with dichroic filters enabled a simultaneously RGB exposure, which made the color balance and overall exposure energy easy to control as well as simplifying the recording procedure. Various approaches have been investigated in generating color hologram which have sufficiently high diffraction efficiency combined with improved color saturation. A specially designed test object consisting of the 1931 CIE chromaticity diagram, a rainbow ribbon cable, pure yellow dots, and a cloisonne elephant was used for color recording experiments. In addition, the Macbeth Color Checker chart was used. Both colorimetric evaluation and scattering noise measurements were performed using the PR-650 Photo Research SpectraScan SpectraCalorimeter.

At the end of the last century, Gabriel Lippmann was experimenting with color photography. His photographic color recording technique, Lippmann photography, produced very beautiful photographs and the fact that the colors are preserved in the early Lippmann photographs indicates something about their archival properties. Recent progress in color reflection holography has made it possible to take a new look at this one hundred year old photographic technique. Today, high-resolution panchromatic recording materials suitable for Lippmann photography are on the market. In particular, the Slavich panchromatic ultra-high- resolution silver-halide holographic materials have been investigated for modern Lippmann photography. Since the color photographs contain no dyes or pigments their archival stability may be high. In addition, a Lippmann photograph is difficult to copy which makes it a unique color photographic recording. Both of these features must attract a photographer interested in creating beautiful art photographs. It is also shown that Lippmann photographs can be made without the mercury reflector, instead by using the reflection from the gelatin-air interface. This eliminates the complications in dealing with mercury, while still maintaining the high resolution and picture quality at the expense of longer exposure times. Security application is a potential field for Lippmann photographs as well as optical filters. Another advantage is that no expensive equipment, such as lasers, is needed to explore this photographic recording technique; only a modified camera is required.

At the end of the last century, Gabriel Lippmann was experimenting with color photography. His photographic color recording technique, Lippmann photography, produced very beautiful photographs and the fact that the colors are preserved in the early Lippmann photographs indicates something about their archival properties. Recent progress in color reflection holography has made it possible to take a new look at this one hundred year old photographic technique. Today, high-resolution panchromatic recording materials suitable for Lippmann photography are on the market. In particular, the color photopolymers from DuPont have been investigated for modern Lippmann photography. Since the color photographs contain no dyes or pigments their archival stability may be high. In addition, a Lippmann photograph is difficult to copy which makes it a unique color photographic recording. Both of these features must attract a photographer interested in creating beautiful art photographs. Security application is another potential field for Lippmann photographs as well as optical filters. The dry processing of the photopolymer material is an important advantage. Another advantage is that no expensive equipment, such as lasers, is needed to explore this photographic recording technique; only a modified camera is required.

Color reflection holograms recorded with the Denisyuk geometry have been demonstrated by the recently formed HOLOS Corporation in New Hampshire. The Slavich red-green-blue (RGB) sensitized ultra-high resolution silver halide emulsion was used for the hologram recording. The employed laser wavelengths were 647 nm, 532 nm, and 476 nm, generated by an argon ion, a frequency doubled Nd:YAG, and a krypton ion laser, respectively. A beam combination mechanism with dichroic filters enabled a simultaneous RGB exposure, which made the color balance and overall exposure energy easy to control as well as simplifying the recording procedure. HOLOS has been producing limited edition color holograms in various sizes from 4' X 5' to 12' X 16'. A 30 foot long optical table and high power lasers will enable HOLOS to record color holograms up to the size of one meter square in the near future. Various approaches have been investigated in generating color hologram masters which have sufficiently high diffraction efficiency to contact copy the color images onto photopolymer materials. A specially designed test object including the 1931 CIE chromaticity diagram, a rainbow ribbon cable, pure yellow dots, and a cloisonne elephant was used for color recording experiments. In addition, the Macbeth Color Checker chart was used. Both colorimetric evaluation and scattering noise measurements were performed using the PR-650 Photo Research SpectraScan SpectraCalorimeter.

Recording of large-format color reflection holograms of the Denisyuk type has been performed in the new HOLOS' color holography facility in New Hampshire. Ultra-high resolution silver-halide emission of the Russian type is employed for the recording. With dichroic filter beam combination in the recording setup, simultaneous red-green-blue exposure is conducted. By this method, the RGB color balance ratio and overall exposure energy on the emulsion can be controlled independently. The facility is equipped with several high- power cw lasers (krypton-ion, argon-ion, and frequency- doubled Nd:YAG) to obtain three suitable laser wavelengths for color hologram production. A 30 foot long optical table enables HOLOS to generate color holograms up to 60 cm by 80 cm.

Color holograms are recorded on silver halide emulsion using multiple wavelengths. The images are reconstructed without shifts in wavelengths. This allows applications in three areas of holography: (a) display holograms yield images that closely resemble the original objects. (b) In holographic interferometry where no prior information is available concerning the locations of zero displacements, there has not been a convenient method which allows the determination of the locations of the zeroth order interference fringes. Using color holography, these fringes appear in white color; thus are automatically identified. (c) Holographic optical elements created using this method greatly enhance operations where multiple wavelengths are involved.

Holographic interferometry is a well established technique for accurate measurements of mechanical displacements. In cases where no prior information is available on the lcoations of zero displacement, there has not been a method which allows one to determine the location of the zeroth order interferometric fringe. We wish to demonstrate that by using three wavelengths to record color interferometric holograms, the zeroth order fringes are easily identified.

Color holograms recorded in panchromatic, single-layer, ultra-high-resolution, silver-halide emulsions have been previously reported. Color reflection holography presents no problems with regards to the geometry of the recording setup, but the final result is highly dependent on the recording material used. The processing of such emulsions is critical in order to obtain high diffraction efficiency and good color rendering. In particular, preventing emulsion shrinkage is extremely important. The recording procedure and the processing steps will be described.

It is well known that particular choice of laser wavelength combination is of great importance in making color holograms. Previously, it was found that the 532 nm wavelength was most suitable for green. Herein we report the results of experiments performed in search of the most suitable blue wavelength. Also discussed will be the procedure and configuration used for the experiments.

Color holograms recorded in panchromatic, single-layer ultra-high-resolution silver-halide emulsions have been previously reported. Color reflection holography presents no problems as regards the geometry of the recording setup, but the final result is highly dependent on the recording material used. The processing of such emulsions is critical in order to obtain high diffraction efficiency and good color rendering. In particular, preventing emulsion shrinkage is extremely important. The recording procedure and the processing steps will be described.

The recording of high-quality color holograms is the only way in which holography can be made truly useful and totally acceptable in the world of business and everyday life. This possibility has been now opened by the introduction of panchromatic, single-layer ultra-high- resolution silver-halide emulsions which make it possible to obtain high-quality, large-format color reflection holograms. The use of three laser wavelengths on a single-layer emulsion in the recording process (Lippmann holography) makes the holographic recording technique similar to the early Lippmann photography of the last century. That combination promotes not only good color rendition but, additionally, due to wavelength multiplexing, the image resolution is improved as compared to monochrome holographic recordings. This fact is important in holographic microscopy and endoscopy, where high-resolution color images are particularly important.

A comparison between Western commercial silver-halide emulsions and the Russian ultra-fine- grained emulsions for holography has been performed. Single-beam reflection holograms of the Denisyuk type were recorded using continuous-wave lasers. This recording scheme was selected since it represents a rather simple and stable holographic setup, but an extremely demanding one on the recording materials. Various processing schemes were applied to obtain high-quality holograms. Phillips' three-step processing technique, fixation-free rehalogenating bleaching, reversal bleaching, and solution-physical development were all investigated. In particular, diffraction efficiency, image resolution, scattering, and signal-to-noise ratio were studied as a function of emulsion and processing method. For comparison, some recordings were also made on other popular materials in common use in holography.

The processing procedures for surface relief holograms recorded on silver halide emulsions are presented. The most promising methods have been investigated and compared. The aim is to develop and optimize methods for obtaining relief structures on silver halide gelatin emulsions for holography at rather high spatial frequencies. Such a relief pattern can then be used for making a metallic matrix. The main advantage of using a silver halide material, instead of photoresist material, is the favorable sensitivity characteristics over the whole visible spectrum of silver materials.

A virtual image replay system has been constructed at the Fermi National Accelerator Laboratory to replay holograms produced in experiment E-632. The holograms were produced by a modified in-line holographic system installed in the 15 ft. bubble chamber detector. The experiment produced 110,000 holograms useful for physics analysis. The holograms were recorded on 70 mm Agfa-Gevaert Holotest 10E75 film. The bubble images represent tracks of charged particles produced from high energy neutrino interactions. Since one of the main purposes of the experiment was to observe short lived particles, our holographic system makes it possible to record smaller bubble images (approximately 100 mm) than possible with conventional photographs (approximately 500 mm) which record the entire visible chamber volume (28 m3) and are subject to the limitations of conventional photography i.e., diffraction of the camera lens aperture. Although the holographic volume is 1.5 m3, 20 - 30% of all the interactions in the bubble chamber fall within the holographic volume since the beam is concentrated in the center of the chamber. An important aspect of the experiment is the inspection of the holograms and for this reason an effective replay system is necessary. We have constructed a low cost replay system and chosen a virtual image replay because it requires much less laser power and this has proven to be a great advantage. We discuss the major components of the holographic replay machine and the relevant design features. Replay wavelengths different than the original recording wavelength are possible and corrected for in the system described. The resolution of the system is improved using a liquid film gate. A fiber optic reconstruction reference beam has been useful and convenient. Examples of replayed bubble chamber events are shown.

Endoscopic holography or endoholography combines the features of endoscopy and holography. It can be utilized in holographic imaging or interferometry inside natural cavities of the body. In imaging, the ability to view a three-dimensional, large focal depth, faithful rendition of internal organs and tissue may greatly enhance the detection of disease and abnormality. Contact Denisyuk holography makes it possible to obtain a high-resolution holographic recording which can be examined microscopically. In the case of endoholographic interferometry, new diagnostic techniques can emerge; e.g., the measurement of compliance of the wall of the bladder or of the arteries may provide diagnostic indicators of early stages of disease.

The first holographic portrait of a President of the United States of America was recorded on May 24, 1991, in Santa Barbara, CA. Ronald Reagan was the subject. The event was the first in a project that began some five years ago with the aim of producing an archive of Presidential pulsed holographic portraits. The authors discuss the inception and evolution of the project. They describe the unique interactions, communications and scheduling as well as trials and triumphs involved in recording a holographic portrait of such a prominent public figure.

The old recipes for Lippmann emulsions are presented as well as processing methods used for Lippmann color photography. These techniques are compared with modern silver halide emulsion preparation used for holography. Western emulsion making as well as the fabrication of the ultra-fine grained emulsions of the Soviet type are described. Processing methods for extremely fine grained emulsions are also presented.

The holographic scientist has a long experience of developing and bleaching methods for the silver halides. There is however
an underlying asymmetry of the chemical armoury. Whilst numerous developers have evolved throughout the history of
photography, there is a paucity of organic bleach compounds that mimic their developing counterparts. This paper discusses
the synthesis of novel bleaches starting with a range of developing agents. The door is opened to relatively safe long-keeping
organic bleach agents with improved toxic hazard levels.

The fracture process on cement based materials was studied using various holographic interferometry methods. Several aspects of the fracture process were studied on plane mortar (cement water and sand) and polypropylene fiber reinforced cement under different loading configurations. Sandwich holography was used to analyze mortar specimens loaded in tension. The real time method was used to determine the load increments required for accurate and easy evaluation of displacements. A single sensitivity vector setup was used for the evaluation of crack opening displacements and a multiple sensitivity vector set-up was used for the evaluation of full displacement fields. In both cases the holographic images were acquired by a digital image analysis system. First the images were enhanced for better recognition of the fringe patterns by elimination of high frequency noise and contrast improvement. Then the image analysis system was used for automatic fringe count. Sandwich holographic interferometry was also used to map the crack surfaces of the mortar specimens tested. The use of image analysis was essential for the evaluation of the interferograms. The image analysis system allowed for the direct application of a moire pattern method resulting in topographic contour maps. Crack pattern characterization on polypropylene fiber reinforced specimens was made using the ''piggy back'' method to record double exposure reflection holograms. Image processing was used for image enhancement and automatic computation of crack spacings. 1.

Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help

Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help to their control. 1.

A presentation of a recording technique for making pulse laser hologram portraits is given. The master recording studio is described as well as the transfer setup used for making reflection copies of pulse masters. A list of references of published papers concerning the art and the technique of making holographic pulse portraits in general, is provided.

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An introduction to the holographic recording process is given, including also the demands on recording materials for holography. The course covers different recording materials for holograms, HOEs, and DOEs, which currently are on the market. In particular, the new improved silver halide (AgHal) emulsions from new sources as well as dichromated gelatin, photopolymer, photoresist, thermoplastic materials, and bacteriorhodopsin are all described.

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Journal of Applied Remote SensingJournal of Astronomical Telescopes Instruments and SystemsJournal of Biomedical OpticsJournal of Electronic ImagingJournal of Medical ImagingJournal of Micro/Nanolithography, MEMS, and MOEMSJournal of NanophotonicsJournal of Photonics for EnergyNeurophotonicsOptical EngineeringSPIE Reviews